Max Verstappen is running a Ferrari 296 GT3 in todays official NLS test on the Nürburgring Nordschleife. He tried to stay unnoticed using the name "Franz Hermann" on his car.

I hope we'll see him do some GT3 racing when he quits F1. Has to be in the cards along with Le Mans, surely?

Interestingly enough, although Max himself has previously done laps in his own team's GT3 car, today he was running with the Emil Frey Racing team who Thierry Vermeulen, son of Verstappen’s manager Raymond, drives for.

And:

According to information from AMuS, Verstappen is reportedly planning to obtain the so-called Nordschleife permit this year. This special racing license is required to take part in official NLS events and the legendary 24-hour race at the Nürburgring.

Source

Considering the current f1 calendar, I'd watch out for alternative tracks, too